The sad fact is that this is universal across nearly all health problems. These are generalizations, there are certainly more explanations than this. But these are my observations from watching how other people with all sorts of conditions relate to their healthcare.
Sometimes people want their doctor to find all the information and answers for them, and they expect they will not need to learn anything themselves, even from the sheets the doctor sends you home with. They believe their doctors will always have the most up to date info. "that's what I'm paying the doctor so much money for so why should I have to learn this?" -this is what my grandpa says.
Sometimes because they are in denial about what is happening to them, that their bodies are not infallible and they will not be here forever. It's an uncomfortable reality to confront regardless of diagnosis. If they don't learn about it, if they don't do things actively to manage it, it's not there. I did this myself many times until I got this disease because I was sick very often throughout my childhood and convinced myself I would never be sick again, hated and avoided doctors like the plague.
Or they push on and deny that anything is wrong because they have to- gotta make money, pay bills, no insurance, no doctor, no money, no choice. That works better in a lot of other illnesses than it does with this one. Or it works longer, not sure which.
Other people will hear that there is nothing wrong or that something is normal once from one (or maybe a couple) doctors or nurses and just believe it must be. I went undiagnosed as having endometriosis for 11 years because of doctors who told me it was normal that I was passing out and vomiting violently from the pain of having my period, and that a variety of less severe symptoms were also normal. By the time I accepted that this was not normal there were endometrial growths on my left ureter and had they gone untreated a few years more I would have lost the use of my left kidney. Even with treatment, my left ovary is no longer kicking out eggs as the fallopian tube is too far gone.
With the above possible roadblocks, it is certain that if something wrong enough or bad enough happens, one's attitude will change. It is possible that those of us that are here used to look at health and disease much differently than we do now. I know that to become a seeker of information myself I had to have the crap scared out of me by how bad I was feeling, and have an encounter with maybe the worst doctor ever to practice medicine. Actually 2 of the worst doctors. But I know I wasn't this proactive to begin with, far from it.
Some people just don't have internet access and they read a lot of books instead. So we just don't know they are right there with us! I've only had steady internet access for about a year, but I was pretty well informed because of the books I'd read.
Sadly, because of the special conditions of our disease there are people with ME/CFS who cannot expend the energy needed to learn and don't have anyone to help them. We have all been there for varied lengths of time- but the very fact that we are here (even if here is minutes at a time on a laptop on a couch and not that often) means that we should consider ourselves lucky.